Air brake



L. PICKERT Nov. 21, 1950 AIR BRAKE Filed March 15, 1948 Snoentor Lgnn LPickzr:

Gttornegs l n IAVIIIIIIII um n @nz f Patented Nov. 21, 1950 v AIR BRAKE i'ynnll lickert, Watertown, Y., assignor to The' York" A'ir'y Brake Company; a`1 corporatio Apmibationivraren15,1948, seria-fno. 14,956 lclaiinsz (C1. Sos-68W This inventionA relatesto air brakes and para" ticularly to an improvement on' the release valve of' the. Pickert Patent' 2392185y dated January? 1, 194:6. A r A In the" allowed' application Of Klein, SelalNOl 733,726, iil'edI March 24, V1947, which" issued on3 July 1'33. 11948 as Patent 254445993 applicantsassignee, there isdescribed andfclai'med" a scheme for venting the retainer pi'pe'otI the rela-ted'-brake--l controlling valve'devi'ce when'the-release valve is in its' brake releasing position; Thismakes itV possible for'theVA release'` valvey tov reseth when the brake-controlling valve device moves to release position. It also-makesitpracticable and'safe to use the releasevalves-to1free a train stopped onV a grade with the retainers set. In certainVV cases this is advantageousbecause the retainers can remain1 set soI as to become eictive in' ensuing cycles of grade' braking;

The-Klein proposalfinvolved the usey of. a check valves To? causas'uchA akvalveto. vent to a very low pressure, tlief valve-seating spring mus-t be light. Ailight springfisapttofallow the valve tov chatter: and wear when the'valve isnot seatedV by' pressure and the-car is vin motion. The present invention;does'awaywiththe checlc valve and providesa wholly'differentivalve for venting the retainer pipe. This valve can be spring-loaded so as never tochatter. Inadditionr to thisfadvantage the valve controls flow onlyA froml the retainer' pipe, sov that its failure. could` bev sig.- nicant only when: retainers arel fsetV and" then only as aecting the,` retaining action.

Practical embodiments of the invention are illustrated in the accompanying, drawing in' which:

Figs 1. is an axial' vertical section of a release valve,.constructed according to s'aid'Pickert patent,Y buty with the present invention applied, the' releaseval've being shown connected with an AB control valve, retainer valve, reservoirsand brake cylinder. I

Fig. 2` is a fragmentaryv sectional View of a slightly modified release valve.

In both views the release' Valve is shown in normal (non-releasng)" position. InVFi'g. 1l the control valve, retainer valve, brakej cylinder" and' pipe connections (all ofwhich follow commercial standards)` are drawn' in miniature' to save space. The AB control valve typies any automatic control valve or triple valve:

The pipe bracket" of an AB control valve' is in'- dicated at 6, the' body of the emergency portion is indicated atl, and the' body of the servicepor'- tion at' 8. The' usual reservoirbleed valve is ind'icatedl at 9. Thisv bleed. valve needrk not bedispensed with, but it wouldy be spplantedrormost' purposes by the. release valve of thepres'ent in- Vention..

The brake pipe' is indicated" at' 'n and has a' branch` which leads throughl a dust" collector I2 to` thepipebracke't. The brakecylinder connecf tion appears at f3", the auxiliary reservoir connection at I4, and the supplemental reservoir connection at |5.v Fragments of the'l two reservoirs appear in the drawingV and are identified byle'gends.

A brakev cylinder isindicated at IE. AThe' ree" leasevalve is interposed between thebrake cylin-f' der' connection'V I3' andthe' brake cylinder i6.- They main`v body portion of the release* valve is' shownat 2| and is in the form of a cored" casting', hav-` ing a chamber 22` and" a chamber 23.. Pipe 23 communicates with chamber 22 andbrake' cylinder pipe' 24^with chamber 23.

VThe' chambers 22 and 23 are separated by alf downwardly presented valve seat 26; This seat' is" shown` as formed' on an insert or spider 21 which is sealed by gaskets 28 and 29 and which is clamped by a body member 3| of the form clearly shown in the drawing.

The body member 3| is bolted to thetop ofthe housing 2 and clamps the peripheralmargin of a lexiblediaphragm 32 shown as of theslackfor corrugated type'.

The lower' side-of the diaphragm is subjected'V to` theA pressure in the chamber 22. The diaV phragm is subiect on its upper side to pressureV in al chamber'3'3 which is connected by a passagel 3'4'with` a chamber" 351forrne'd inA the lower end of" the housing 2|. The' chamber 23 and the chambercommunicate with each other through the bore of a bushing 36 which is pressed into an opening extending between these two chambers. The bushing 36 has lateral ports 31 which communicate with' an annular passage 38 and through" the passage' 33 with a passage 34 and consequently with the chambers 33 and 35'.

Controlling discharge" from' the bottom of the' chamber 35 is an upwardly presented valve seat An upwardly extending stem 44 passes throught the center ofthe diaphragm 32- and is clamped to the center of the diaphragm by a flanged' sleeve @5ly a thrust plate 46",. which. overlies the diaphragm, and a nut 41.

The plate 46 is biaseddownward by a coil com'- pressionspring. 48, so.- thatY valve 42 is normally seatedy andthevvalve 43" open. Spring 4'81 reacts betweenplate 4'5and` a ported plate 49 which fitsv a marginal'rebate formed inA member 3i at the top of chamber 331 Over ported plate 49; is a exible diaphragm lfrwhich. is clamped at its margin by cap 52. In cap 52 is a valve chamber 53L tov` which a passage 54l leads' tlfirough avalve seat 55. yPassage 54 is connected by pipe 56 with the exhaust pipe 51 which leads from the control valve to a retainer 58 of any usual form.

The chamber 53 is vented to atmosphere at 59. A disc 6| is seated on diaphragm 5| and urged downward by coil compression spring 62. Disc 6| has a rubber-like sealingface 63 arranged to engage valve seat 55 when the plate is forced upward by the diaphragm A pilot 64 is provided to hold the disc centered.

The lower end of valve body 4| makes a free fit in bushing 35, whereasthe upper end, beneath valve 53 is reduced in diameter. A peripheral groove 53 defines an encircling iiange 25. Flange 25 is so located that when valve B2 is closed the flange 25 fully exposes ports 31. A diagonal port G5 connects the annular clearance above flange 25 with groove (i5. The ange also makes a free iit in thel bushing 33. The flange is so located that if body il is moved up sufliciently to close valve d3 against seat 25 the ports 31 are throttled but not closed.

A housing 5i of the form shown is attached to the bottom of the housing 2| by machine screws, one of which appears at 38. The housing 51 has an internally iianged opening in its lower end in which is mounted a universally tiltable actuator comprising a ported head 69 which seats at its margin on the internal flange in housing 61 and which has at its lower end a fork il to which an actuating rod may be attached.

Resting on the head 59 is the lower end of a stem 12 which is guided by a guideway formed in a spider i3 clamped between the housings 2| and El'. The rim of the spider has through-ports as shown. The stem 12 is biased downwardly by a spring 13. Ii the head 53 is tilted in any direction the eiiect is to force the stem i2 upward, and since the stem 12 is aligned with the valve body ril, the effect of tilting the head 69 is to force the valve body 11| upward against the resistance of spring i8 so as to open the valve 42, throttle the ports 31 and close the valve 43.

Modification of Fig. 2

The embodiment shown in Fig. 2 is basically the same and parts essentially identical with parts in Fig. l are identiiied by the same reference numbers increased by 100.

rlhe differences are few and can be briefly stated. Instead of the ported plate 49 the member |3 has an iinperforate partition 33 above chamber |33. Thus the diaphragm |5| is not directly subject on its lower side to pressure in chamber E33. Instead, it is subject to pressure in chamber |23 and brake cylinder I6 which are connected with it by a passage 4|).

Actually the difference is not great, for chamber 23, passage 35 and chamber 33 of Fig. l are always in communication with brake cylinder I6 and hence at substantially the same pressure. The term substantially is used advisedly for retardation of flow through ports does produce moderate differentials of pressure, at times.

The second arrangement has a slightly better timing margin, but the first, on test, has demonstrated wholly satisfactory characteristics. Relatively remote chambers such as 33 and 23 or |33 and E 23 are characterized by diierent rates of pressure rise and fall. These aiect timing, but not enough to impair operative characteristics.

Operation A description of operation with reference to Fig. 1 will suice for both constructions.

Whenever cylinder I6 is under pressure, this pressure acting upward on diaphragm 5I (|5|) closes valve 63 (|63), so there is then no secondary vent from the retainer pipe 51. This is true (assuming an ordinary three-position retainer) whether theretainer is in position l (free exhaust) position 2 (1() pounds retained), or position 3 (20 pounds retained).

Suppose a train stalls with retainers in position 3. If a brakeman leaves retainers in position 3, but operates several release valves by pulling their yokes 1| the corresponding valves 4| will move up and stay up, venting the related brake cylinders and blanking their pipes I3 by the closure of valves 43 on seats 26. Venting of brake cylinders permits the train to move, but it also opens valves 63, venting the corresponding retainer pipes 51. In grade cycling the engineer builds up brake pipe pressure to move the AB valves to release position and permit recharging of reservoirs. The resulting fall of pressure in chambers 23 (possible because the retainer pipes are vented) causes those release valves which had been manipulated, to reset, On the ensuing reapplication those brakes which had been released by the release valves will re-apply, and the reapplication will thereafter be retained by the set retainers.

The ultimate result is thus basically the same as that secured by the Klein construction, but the operation is more certain and is carried out by apparatus which is not affected by vibration.

The valve of the present invention attains all the results of the original Pickert device, affords an additional useful function, requires only one additional pipe (pipe 56), and incorporates the bleed valve for the retainer pipe in the vent valve structure, so that the whole device can be shipped and applied as an assembled, factorytested unit.

The invention as embodied in Fig. 2 offers possibilities of arrangement which should not be overlooked. The valve |63 and its actuating diaphragm |5| are associated with the release valve in housings |2| and |3| only as a matter of convenience. From the standpoint of the two ow- 'connections |54 and 40, the valve |63 and its and release valve on particular cars.

- for some special service and the invention offers an opportunity to install according to the needs of any given case.

This amounts to saying that the valve |63, actuating diaphragm |5|, biasing spring |62 and the necessary housing form a complete functional entity, namely a normallyY open valve which vents the retainer pipe independently of the retainer whenever the brake cylinder is vented, and closes as soon as the brake cylinder is put under pressure, so that the retainer is rendered potentially eiective by a brake application and disabled by venting the brake cylinder, however this isV eiected.

Two practical embodiments of the invention have been described and the possibility of others has been explained. Hence the invention is broader than any particular embodiment. Its scope will be defined solely by the claims.

What is claimed is:

1. In an automatic air brake system, the combination of a brake pipe; an auxiliary reservoir; an automatic control valve connected with said brake pipe and auxiliary reservoir and having a brake cylinder connection and an exhaust connection; a brake cylinder connected with the f brake cylinder connection; a retainer valve operable independently of any pressure in the system to control flow from said exhaust connection; a normally open secondary valve controlling an auxiliary vent from said exhaust connection; and a pressure motor subject to pressure in the brake cylinder and serving when subjected to pressure to close said secondary valve.

2. The combination of the structure defined in claim 1 and yielding means biasing said secondary valve toward its open position.

3. In an automatic air brake system, the combination of a brake pipe; an auxiliary reservoir; an automatic control valve connected with said brake pipe and auxiliary reservoir and having a brake cylinder connection and an exhaust connection; a brake cylinder connected with the brake cylinder connection; a retainer valve settable to control iiow from said exhaust connection; a normally open secondary valve controlling an auxiliary vent from said exhaust connection; a pressure motor subject to pressure in the brake cylinder and serving when subjected to pressure to close said secondary valve; a dual valve interposed in the brake cylinder connection between the control valve and the brake cylinder, said dual valve having a normal position in which it opens said connection, and an abnormal position a brake cylinder connection and an exhaust connection; a brake cylinder connected with the brake cylinder connection; a retainer valve settable to control flow from said exhaust connection; a normally open secondary valve controlling an auxiliary vent from said exhaust connection; a pressure motor subject to pressure in the brake cylinder and serving when subjected to pressure to close said secondary valve; and a release mechanism interposed in the brake cylinder connection between the control valve and the brake cylinder, said mechanism comprising a dual valve having a normal position in which it opens said connection and an abnormal position in which it closes said connection and vents the brake cylinder, pressure-responsive means serving to retain said dual valve in abnormal position when in said position and subject to brake applying pressure by the control valve, and to restore it to normal position when said pressure is released by the control valve, and operator-operated means for moving said dual valve to abnormal position.

5. In an automatic air brake system, the combination of a brake pipe; an auxiliary reservoir; an automatic control valve connected with said brake pipe and auxiliary reservoir and having a brake cylinder connection and an exhaust connection; a brake cylinder connecter' with the brake cylinder connection; a retainer valve settable to control flow from said exhaust connection; a normally open secondary valve controlling an auxiliary vent from said exhaust connection; a pressure motor subject to pressure in the brake cylinder and serving when subjected to pressure to close said secondary valve; and a self-restoring releasing mechanism interposed in said connection and comprising an expansible chamber motor having two Working spaces separated by a movable abutment the iirst working space being subject to braking pressures established by the brake controlling valve device, a dual valve connected with said abutment to be shifted thereby between two positions, namely a normal position assumed when the abutment is shifted toward the first working space and in which the dual valve connects the brake cylinder and the brake controlling valve device and also connects the two working spaces, and an abnormal position in which the valve interrupts the two connections just mentioned and vents the brake cylinder and the second working space, yielding means insuiiicient to resist eiective braking pressure in the rst braking space and serving to bias the abutment toward said normal position and manually operable means for causing said valve to shift to said abnormal position.

6. In an automatic air brake system, the combination of a brake pipe; an auxiliary reservoir; an automatic control valve connected with said brake pipe and auxiliary reservoir and having a brake cylinder connection and an exhaust connection; a brake cylinder connected with the brake cylinder connection; a retainer valve settable to control now from said exhaust connection; a normally open secondary valve controlling an auxiliary vent from said exhaust connection; a valve closing pressure motor serving when subjected to pressure to close said secondary valve; a selfrestoring releasing mechanism interposed in said connection and comprising an expansible chamber motor having two working spaces separated by a movable abutment the first working space being subject to braking pressures established by the brake controlling valve device, a dual Valve connected with said abutment to be shifted thereby between two positions, namely a normal position assumed when the abutment is shifted toward the first working space and in which the dual valve connects the brake cylinder and the brake controlling valve device and also connects the two working spaces, and an abnormal position in which said valve interrupts the two connections just mentioned and vents the brake cylinder and the second working space, yielding means insufcient to resist effective braking pressure in the first braking space and serving to bias the abutment toward said normal position and manually operable means for causing said valve to shift to said abnormal position; and a pressure-transmitting connection between said econd working space and said valve-closing mo- LYNN I. PICKERT.

REFERENCES CITED The following references are of record in the file of this patent'L UNITED STATES PATENTS Number Name Date 1,131,181 Turner Mar. 9, 1915 2,392,185 Pickert Jan. 1, 1946 

